High Sierra Security Update Jan 2020 Problem

Today, I followed the update procedure of Apple to update to the latest MacOS Security updates. And… it didn’t go so well…

I tried the old PRAM reset and also an SMC reset as well. It still didn’t work. I got in to the recovery part as well, and was able to do a first aid on the disk. It all checked out well.

I also tried Safe Mode, but that didn’t really work properly, but it did spit out a lot of good information. I spotted something along lines of it hanging on a KEXT or similar.

Nothing really worked and it just stayed on this window, it basically looks like it’s hung…

After a few hours, nothing.

So I went to an Apple store, and asked for the most geeky non-retail person. They didn’t have what I needed, so have now booked in to see a genius.

I came home and thought I’d try and fix it again.

I came across this website.


So, instead I tried this and logged in via Single User mode and followed this section.

The OS X Fix You’ve Been Looking For

I was ultimately able to surmise that the issue was an incompatible kernel extension (kext file). After booting into Recovery Mode, I opened Terminal. First I mounted the filesystem as read write, then navigated to /Volumes/Macintosh HD/Library/Extensions, created a new folder named “Unsupported” and moved all the kext files into it, then rebooted.

Note: see the updated script at the very bottom of this post to automatically remove non-default kexts. If you have renamed your hard drive to something other than “Macintosh HD” use the new name in the following commands.

mount -rw /
cd /Volumes/Macintosh\ HD/Library/Extensions/
mkdir Unsupported
mv *.kext Unsupported


So, in short, it was as I suspected, to be a suspect KEXT file.

This will get you out of trouble.



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